Two beams, A and B of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero

Question

Two beams, A and B of plane polarized light with mutually perpendicular planes of polarization are seen through a polaroid. From the position when the beam A has maximum intensity (and beam B has zero intensity), a rotation of polaroid through 30^omakes the two beams appear equally bright. If the initial intensities of the two beams are I_Aand I_Brespectively, then $\frac{I_{A}}{I_{B}}$ equals :

Options:

Answer:

D

Solution:

$I_{A} {cos}^{2} θ = I_{B} {cos}^{2} (90 - θ)$ $(I = I_{0} {cos}^{2} θ)$ by malus equation

$∴ \frac{I_{A}}{I_{B}} = {tan}^{2} θ = \frac{1}{3}$

where $θ = 3 0^{o}$

TestHub · Accepted Answer

I A cos 2 θ = I B cos 2 9 0 - θ I = I 0 cos 2 θ by malus equation ∴ I A I B = tan 2 θ = 1 3 where θ = 3 0 o

Physics - Wave Optics Question with Solution | TestHub

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